Estrogen Discouraged for Disease Prevention

April 13, 2004 -- Women who are still taking estrogen to prevent chronic conditions like heart disease should stop, government officials now say. Long-awaited results from a large prevention study show that menopausal hormone therapy with estrogen alone neither increases nor decreases heart disease risk.

The findings are being published just over a month after the estrogen-only arm of the prevention study known as the Women's Health Initiative (WHI) was halted early. The study concludes that estrogen alone does not appear to affect heart disease. Earlier results showed that combination estrogen/progestin treatment increased heart disease risk.

But the researchers also concluded that estrogen therapy alone in postmenopausal women, like combination treatment, appears to increase the risk of stroke.

They say that the increased risk of stroke associated with the long-term use of estrogen alone outweighed any of the disease-prevention benefits found during the study.

In a news conference held Tuesday morning to discuss the findings, National Heart, Lung and Blood Institute Acting Director Barbara Alving, MD, said it is now clear that hormone therapy is not the disease-prevention panacea it was once believed to be.

"Hormones are certainly very appropriate for the treatment of menopausal symptoms, but they should be used at the lowest effective doses for the shortest possible time," she said. "For the prevention of diseases such as cardiovascular disease, hormone therapy is not the answer."

New Findings

The WHI estrogen-only trial included nearly 11,000 healthy postmenopausal women aged 50-79 who had had a hysterectomy. They were treated daily with either the widely prescribed estrogen formulation Premarin or a placebo. The average age of the women at the time of enrollment was 64, and the women took the estrogen or the placebo for an average of seven years.

The study showed that women taking Premarin did not have a lower risk of heart disease. But women taking estrogen alone did have a significantly higher risk of stroke -- 39% increased risk compared with women taking placebo.

The findings are published in tomorrow's issue of TheJournal of the American Medical Association.